diff --git a/lib/tunnelbroker/secondary-tunnelbroker-connection.js b/lib/tunnelbroker/secondary-tunnelbroker-connection.js
--- a/lib/tunnelbroker/secondary-tunnelbroker-connection.js
+++ b/lib/tunnelbroker/secondary-tunnelbroker-connection.js
@@ -2,7 +2,10 @@
 
 import type { MessageToDeviceRequest } from '../types/tunnelbroker/message-to-device-request-types.js';
 import type { MessageToTunnelbrokerRequest } from '../types/tunnelbroker/message-to-tunnelbroker-request-types.js';
-import type { TunnelbrokerAPNsNotif } from '../types/tunnelbroker/notif-types.js';
+import type {
+  TunnelbrokerAPNsNotif,
+  TunnelbrokerFCMNotif,
+} from '../types/tunnelbroker/notif-types.js';
 
 type RemoveCallback = () => void;
 
@@ -12,7 +15,8 @@
     message:
       | MessageToDeviceRequest
       | MessageToTunnelbrokerRequest
-      | TunnelbrokerAPNsNotif,
+      | TunnelbrokerAPNsNotif
+      | TunnelbrokerFCMNotif,
   ) => mixed,
   // Active tab receives messages from inactive tabs
   +onSendMessage: (
@@ -20,7 +24,8 @@
       message:
         | MessageToDeviceRequest
         | MessageToTunnelbrokerRequest
-        | TunnelbrokerAPNsNotif,
+        | TunnelbrokerAPNsNotif
+        | TunnelbrokerFCMNotif,
     ) => mixed,
   ) => RemoveCallback,
 
diff --git a/lib/tunnelbroker/tunnelbroker-context.js b/lib/tunnelbroker/tunnelbroker-context.js
--- a/lib/tunnelbroker/tunnelbroker-context.js
+++ b/lib/tunnelbroker/tunnelbroker-context.js
@@ -20,7 +20,10 @@
   tunnelbrokerMessageTypes,
   tunnelbrokerMessageValidator,
 } from '../types/tunnelbroker/messages.js';
-import type { TunnelbrokerAPNsNotif } from '../types/tunnelbroker/notif-types.js';
+import type {
+  TunnelbrokerAPNsNotif,
+  TunnelbrokerFCMNotif,
+} from '../types/tunnelbroker/notif-types.js';
 import type {
   AnonymousInitializationMessage,
   ConnectionInitializationMessage,
@@ -61,7 +64,9 @@
     message: TunnelbrokerClientMessageToDevice,
     messageID: ?string,
   ) => Promise<void>,
-  +sendNotif: (notif: TunnelbrokerAPNsNotif) => Promise<void>,
+  +sendNotif: (
+    notif: TunnelbrokerAPNsNotif | TunnelbrokerFCMNotif,
+  ) => Promise<void>,
   +sendMessageToTunnelbroker: (payload: string) => Promise<void>,
   +addListener: (listener: TunnelbrokerSocketListener) => void,
   +removeListener: (listener: TunnelbrokerSocketListener) => void,
@@ -316,7 +321,8 @@
     request:
       | MessageToDeviceRequest
       | MessageToTunnelbrokerRequest
-      | TunnelbrokerAPNsNotif,
+      | TunnelbrokerAPNsNotif
+      | TunnelbrokerFCMNotif,
   ) => Promise<void> = React.useCallback(
     request => {
       return new Promise((resolve, reject) => {